The present invention relates to a manufacturing technology of a semiconductor device, in particular, to a technology effective when applied to a manufacturing step of a semiconductor device for filling a metal film, via a barrier metal film, in a connecting hole opened in an insulating film.
Japanese Patent Laid-Open No. 2004-363402 discloses a method of forming a Ti layer on at least the inner wall and bottom portion of a contact hole penetrating an insulating layer, nitriding the Ti layer with N radicals to form a TiN layer on the Ti layer, and filling a conductive layer in the contact hole (refer to Japanese Patent Laid-Open No. 2004-363402, Paragraphs [0026] to [0028], FIGS. 4 and 5).
Japanese Patent Laid-Open No. 2006-179645 discloses a method of forming a contact hole in an interlayer insulating film, forming a Ti film so as to cover the contact hole therewith, and subjecting the Ti film to plasma nitriding treatment to form a TiN film on the bottom surface of the contact hole (refer to Japanese Patent Laid-Open No. 2006-179645, Paragraphs [0038] to [0040], FIG. 2).
Japanese Patent Laid-Open No. 2005-79543 discloses a method of forming a Ti film over a substrate by CVD, oxidizing the surface of the Ti film, and nitriding the surface of the Ti film to form a TiN film (refer to Japanese Patent Laid-Open No. 2005-79543, Paragraphs [0044] to [0048], FIG. 5).